As a conventional technology of this sort, there is one disclosed in Patent Document 1. FIGS. 4A and 4B are views illustrating a conventional technology substantially equal to the vibration-damping support device disclosed in Patent Document 1, in which FIG. 4A is a front view and FIG. 4B is a cross-sectional view taken in the direction of arrow “F” of FIG. 4A.
The conventional technology illustrated in FIGS. 4A and 4B is directed to a vibration-damping engine support device to be installed on a machine such as a construction machine that is subjected to extreme vibrations in the vertical direction. This vibration-damping engine support device has a rubber mount 22, a support member supporting the rubber mount 22 thereon, specifically a support bracket 23, and stoppers 28,29. The mount is attached to a mounting platform 21a for an object to be damped, specifically an engine 21, and has an elastic member 22a for absorbing vibrations of the engine 21 in the up-and-down direction and in the left-to-right direction, that is, the horizontal direction. The stoppers 28,29 prevent an excessive deformation of the elastic member 22a of the rubber mount 22 under vibrations of the engine 21, and are each formed in a shallow cup shape.
The stopper 28 is arranged on an upper side of the support bracket 23, while the stopper 29 is arranged on a lower side of the support bracket 23. The stopper 28 arranged on the upper side is integrally attached to the mounting platform 21a for the engine 21 via a bolt 25, and the stopper 29 arranged on the lower side is integrally attached to the bolt 25. The elastic member 22a of the rubber mount 22 is held between the upper stopper 28 and the lower stopper 29.
It is to be noted that the vibration-damping support device is held beforehand such that, when it is attached to the mounting platform 21a for the engine 21, the stopper 28 and the elastic member 22a of the rubber mount 22 sag under the weight of the engine 21 itself. As a result, the clearance between the stopper 28 and the support bracket 23 becomes smaller than that between the stopper 29 and the support bracket 23. Consequently, the prevention of a deformation of the elastic member 22a under vibrations of the engine 21 in the vertical direction is achieved primarily by a contact of the upper stopper 28 to the support bracket 23.
According to the conventional technology constructed as described above, when the engine 21 is driven and vibrates in the vertical direction and horizontal direction, vibrations of the engine 21 are absorbed by deformations of the elastic member 22a of the rubber mount 22. Even when vibrations of the engine 21 in the vertical direction become large and the upper stopper 28 arranged integrally with the engine 21 comes into contact with an upper surface of the support bracket 23, the elastic member 22a is prevented from any further, excessive deformation. If vibrations of the engine 21 in the vertical direction become significantly large, for example, occasionally for any reason, the lower stopper 29 comes into contact with a lower surface of the support bracket 23. As a consequence, any excessive deformation of the elastic member 22a is prevented.
Any excessive deformation of the elastic member 22a of the rubber mount 22 under vibrations of the engine 21 is prevented by the stoppers 28,29 as described above, and the elastic member 22a is protected from damage. Therefore, durability of the rubber 22 is secured.    Patent Document 1: JP-A-9-177888